For example, a vibration proofing apparatus serving as an engine mount is arranged between an engine as a vibration generating portion of a vehicle and a vehicle body as a vibration receiving portion, and the vibration proofing apparatus absorbs a vibration generated by the engine, and attenuates and absorbs the vibration transmission to the vehicle body side. As the vibration proofing apparatus mentioned above, there has been known a liquid sealing type structure in which an elastic body, a pressure receiving liquid chamber and an auxiliary liquid chamber are provided in an inner portion of the apparatus, and these liquid chambers are communicated with each other through a limit passage. In accordance with the liquid sealed type vibration proofing apparatus, in the case that the mounted engine is actuated and the vibration is generated, the vibration is absorbed due to a vibration attenuating function of the elastic material, a viscous resistance of the liquid circulating within an orifice communicating between a pair of liquid chambers and the like, and the vibration transmission to the vehicle body side is suppressed.
As a conventional liquid sealed type vibration proofing apparatus, for example, there is a structure shown in patent document 1. A vibration proofing apparatus described in the patent document 1 has a tubular attachment, a mounting attachment arranged in an inner peripheral side of the tubular attachment, and an elastic body elastically coupling the mounting attachment to the tubular attachment. The vibration proofing apparatus is provided with an upper liquid chamber having the elastic body as a part of an inner wall, a lower liquid chamber having a diaphragm as a part of a partition wall, and a first orifice communicating these liquid chambers with each other, and is provided with four peripheral liquid chambers C1, C2, D1 and D2 arranged along a peripheral direction between the tubular attachment and the elastic body and each having the elastic body as a part of an inner wall. The vibration proofing apparatus is also provided with a second orifice communicating two (a set of) peripheral liquid chambers C1 and D1 adjacent to each other among these four peripheral liquid chambers, and a third orifice communicating the other set of peripheral liquid chambers C2 and D2.
In the vibration proofing apparatus structured as mentioned above, in addition to the upper liquid chamber and the lower liquid chamber communicated with each other by the first orifice, since four peripheral liquid chambers C1, C2, D1 and D2 are provided between the tubular attachment and the elastic body, the peripheral liquid chambers C1 and D1 are communicated with each other by the second orifice, and the peripheral liquid chambers C2 and D2 are communicated with each other by the third orifice, it is possible to effectively attenuate and absorb the vibration along a lateral direction or a longitudinal direction of the vehicle due to an inner friction of the elastic body, a viscous resistance of the liquid circulating through the second and third orifices, and the like, in addition that it is possible to attenuate and absorb the vibration due to the inner friction of the elastic body, the viscous resistance of the liquid and the like at a time of inputting the vibration in a vertical direction, in the case of being applied as the vibration proofing apparatus of the engine of the vehicle.
Patent Document 1: Japanese Patent Application Laid-Open (JP-A) No. 2004-68938 (FIG. 1)